World Wildlife Day is marked on March 3. It was proposed on 20 December 2013 at the 68th session of the UN General Assembly to celebrate and raise awareness of the world’s wild fauna and flora. Since 1963, the International Union for Conservation of Nature (IUCN) maintains the world's most comprehensive inventory of the global conservation status of biological species, the IUCN Red List of Threatened Species. Species are classified by the IUCN Red List into nine groups: extinct, extinct in the wild, critically endangered, endangered, vulnerable, near threatened, least concern, data deficient and not evaluated.